-42.18% is the change from 870 to 503
Calculation steps:
[( 503 - 870 ) ÷ 870] x 100 = -42.18%
Formula
Percentage change = [(503 - 870) / 870] x 100
Subtract the new number by the original number
503 - 870 = -367
-367 ÷ 870 = -0.4218390804597701
-0.4218390804597701 x 100 = -42.18%